The Operations, Clinical Assessment and Administrative Core oversees this entire project and[unreadable] is responsible for the conduct of the clinical trial and the collection of biological and behavioral[unreadable] data. Based on studies of groups of major depressive disorder (MDD) patients, any single[unreadable] psychotherapeutic or pharmacological strategy in clinical practice today achieves remission in only[unreadable] a minority of patients. Thus the initial treatment an individual with MDD receives is largely an[unreadable] accident of chance rather than an evidence based choice. Over a 5-year period, 400 treatment[unreadable] naive patients with MDD will be recruited into a 12 week treatment trial of randomly assigned[unreadable] treatment with an SSRI, escitalopram, a dual 5-HT/NE re-uptake inhibitor, duloxetine or cognitivebehavior[unreadable] therapy (CBT). Subjects will be evaluated using state-of-the-art clinical assessments prior[unreadable] to, during and at the end of acute treatment period. This core describes the efforts that will result in[unreadable] the identification, recruitment of the patients, and assessment and delivery of the treatments. A[unreadable] unique component of this proposal is the study of individuals with MDD not contaminated by[unreadable] previous treatments that may confound measures of treatment response. Commensurate with the[unreadable] CIDAR goals, the data generated in this core will provide the critical foundation for hypothesis[unreadable] generation and testing in the other cores and projects.